They will be fine potted and as houseplants for the winter. If you are buying decent sized plants they might blossom for you inside later this fall. Depending on their size you can let them go dormant and bring them out in the spring. To take them into dormancy I just bring them into a dark cool room where it won't freeze and forget about them until spring. Mine are large by fall so I cut them up and I give away the cuttings. That way I mostly have just bare pots with roots.

You can do it, I'm in zone 5 and have been growing them for years. One thing to be aware of if you grow them over the winter indoors is that bugs love them. Mealy bugs, aphids, spidermites. You want to be armed with product for the probability of doing battle during the winter. I haven't tried to put a plant smaller than 4' tall into dormancy. I think they need a woody stem for that, but then it's the most convenient way to overwinter them.
Depending on the individual plant, you might get a bloom before frost, and you may very well get some during the winter if grown as a houseplant. That's always exciting!

Like other northerners I carry over brugs in dormancy unless they're new/small in which case I try to give them a good southerly window or under lights if really small. Personally, I've found it beneficial to give the rootballs in 2-3 gallon pots a drench of systemic insecticide before bringing them in (need to 'settle' the dirt around the rootball anyhow). I seem to have had fewer insect infestations if I do this, particularly if I inadvertently let things dry out too much when every spider mite in 10
counties finds its way through subzero temps to my basement - LOL! Hope this helps in any way.
Will